O R G A H O L E P T I C TESTS DEVELOPED FOR M E A S U R I I G

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1 111. O R G A H O L E P T I C TESTS DEVELOPED FOR M E A S U R I I G T H E P A L A T A B l L l T Y O F NEAT B E L L E LOWE I O W A S T A T E COLLEGE No one r e a l i z e s b e t t e r than t h e author, t h a t an adequate presentation of scoring cannot be presented i n 20 minutes. For each point t h a t i s mentioned, several others a r e omitted, I n addition, t h e points presented cannot be discussed r u l l y. It i s hoped, however, that t h e material t h a t i s presented w i l l promote discussion from t h i s group. The Necessity f o r Organoleptic Scores Objective t e s t s a r e excellent i n f i e l d s o f research i n whioh performance can be determined by objective t e s t s. There a r e no objective t e s t s for evaluating c e r t a i n factors upon which acceptability depends i n r a t i n g t h e v a r i a t i o n s between samples o f meat o r other foods. I n addition, it seems unlikely t h a t usable, v a l i d objective t e s t s f o r e v a u a t i n g c h a r a c t e r i s t i c s such a8 odor and taste of meat w i l l be developed within a short time. Hence, it seems wise t o use a l l objective t e s t s t h a t give u s e m information i n evaluating scoring data and t o spend time i n elucidation of the complicating f a c t o r s i n organolept i c scoring. Much thought has been put upon t h e selection of scoring panels and the development of score cards. Food technologists, however, r e a l i z e t h e r e i s s t i l l much t o do along these l i n e s. I n addition t e s t s need t o be standardized i n order t o b e t t e r compare r e s u l t s from d i f f e r e n t laboratories. One of the major d i f f i c u l t i e s i n organoleptic t e s t s i s t h e separation of the p a l a t a b i l i t y f a c t o r s. Students constantly comment on t h i s point when they s t a r t scoring. It ta,kes mental d i s c i p l i n e and t r a i n i n g t o separate and f a i r l y evaluate t h e flavor of a product i f t h e texture i s unacceptable o r vice versa. Even one p a l a t a b i l i t y factor, t h a t of t a s t e, may be complicated. There a r e four t a s t e perceptions, b i t t e r, sour, salt, and sweet. We a r e f u r t h e r t o l d that a l l four tabtee a r e intimately connected and t h a t t h e presence of any one taste a f f e c t s and m y modify t h e other t h r e e t a s t e s (Moncrieff, p. 1 2 ). Crocker i n a study published i n 1948 s t a t e s t h a t raw beef when cold has only a weak odor. The taste is sweetish, s a l t y, and generally bloodlike When t h e beef i s warmed, considerable odor develops. It i s a l k a l i n e and m e l i k e a mixture of amines, including piperdine. It i s also somewhat eggy, indicating t h e presence of sulfur compounds. The t a s t e i s mild, pleasant, pers i s t e n t, and chiefly sweet and s a l t y. Crocker found most of the meat flavor came from the meat f i b e r, With longer cooking the flavor increased, reaching an optimum i n 3 t o 3.5 hours of boiling, then with longer cooking t h e flavor decreased. Crocker concluded t h a t cooked-beef f l a v o r i s quite complicated chemically, and consists more of odor than taste. Hydrogen sulfide, amines of several kinds including a low simple form, one of t h e piperdine type, and possible indole were present. The vegetable type odors imply the presence of v o l a t i l e acids. The only elements of t r u e t a s t e noted were sweetness and s a l t i n e s s, no doubt owing t o blood salts. Astringency was noted i n beef ext r a c t s as w e l l a8 in cooked fiber. Many of these constituents a r e associated i n our minds &from our chemistry days as unpleasant odors. Yet t h e s m a l l concentrations present and the combination bring about the fragrant, appetizing '

2 112. odor of cooked meat, None of Crocker's work included flavor developed on t h e surface of t h e meat during Prying, roasting, etc. Lamb, pork, and chicken all d i f f e r e d from beef i n c e r t a i n flavor c h a r a c t e r i s t i c s. Enough of Crocker'a r e s u l t s have been included t o indicate that scoring meat flavor i s not a simple process, and that t h e flavor i s developed t o an optimum during cooking, then decrease8 with longer cooking. Since Crocker (1948) found that t h e flavor was increased by cooking, it follows that t h e c h a r a c t e r i s t i c flavor of meat i s a breakdown product by cooking or i s released from meat upon cooking. Work a t t h e university of California (Bouthilet, 1949) indicates the flavoring property i n chicken meat i s a weak acid produced by cooking. The Score Card The score card should be prepared with care and above everything should be simple. A very complicated score card only frustrates the scorer and a l l too often ends with no s i g n i f i c a n t variations having been found. The number of f a c t o r s t o be scored should be kept as smll as possible i n r e l a t i o n t o the information sought i n the study. If four p a l a t a b i l i t y f a c t o r s a r e used, they may be aroma, flavor i n i t s wider sense, tenderness, and juiciness. Flavor of fat and texture may be added, although some cuts of c e r t a i n meats such as veal have l i t t l e f a t f o r acoring. I f flavor i s t o be divided i n t o i n t e n s i t y and d e s i r a b i l i t y, then t h i s i s d i f f i c u l t scoring and a t l e a s t two o r three p a l a t a b i l i t y f a c t o r s should be eliminated (such a s t e x t u r e and tenderness o r juiciness) t o give t h e scorer time t o concentrate on the points being scored. I t i s unfortunate from some standpoints t h a t numerical r a t i n g s must be assigned to p a l a t a b i l i t y f a c t o r s for acceptability i s not b a s i c a l l y a mathematical f'unction. A score of 4 does not imply that the sample i s twice a s palatable a8 one with a score of 2, nor that it i s two-thirds as acceptable as a sample with a score of 6. But, numerical r a t i n g s a r e p r a c t i c a l l y our only means of evaluating the results' s t a t i s t i c a l l y and f o r making comparisons with other laboratories. Nothing i s gained by using a scoring system that has a range of numbers beyond t h e number of gradations of quality that can be recognized, On t h e other hand using a range of numbers smaller than t h e range of q u a l i t i e s t h a t can be recognized i s a l a o disadvantageous. Since there i s a tendency t o use only the numerical r a t i n g s between t h e top and bottom scores a range of 0 t o 5 w i t h 1 point variation i s less than the gradations of quality f a c t o r s t h a t can be recognized, A range of q u a l i t i e s l e easier t o remember i f descriptive terms a r e assigned t o each numerical r a t i n g. For example, i f scores of 0 t o 10 a r e used, 10 might be assigned t h e word perfect f o r a description, 9 excellent, 8 very good, 7 high average, 5 average, 4 low average, 3 f a i r, 2 poor, 1 very poor, and 0 unacceptable, Varying degrees of i n e d i b i l i t y can be assigned negative r a t i n g s, Some p a l a t a b i l i t y f a c t o r s have a limited range of q u a l i t i e s t h a t can be recognized, but tenderness, i f based upon the number of chews t o masticate a standard s i z e sample t o a determined end point, has a wide range of tenderness variations.

3 113. The Scoring Panel Variation i n organoleptic scoring i s admitted. Even a person who i s o r d i n a r i l y an almost perfect scorer may be thrown o f f base when he has a head cold. Hence, no hard and fast r u l e can be made concerning t h e numbers o f scores f o r a panel. Probably four scorers i s t h e minimum number. However, a s t i l l smaller panel composed o f members who have high s e n s i t i v i t y and a b i l i t y t o d i f f e r e n t i a t e perceptions may be preferable t o a l a r g e group w i t h less s e n s i t i v i t y. One of t h e basic t e n e t s of t h e s t a t i s t i c a l treatment of t h e scoring data i s t h a t a l a r g e r number of individuals a r e needed f o r t h e panel when t h e v a r i a t i o n i n scoring i s great. A l a r g e r number of scorers will a l s o tend t o rule out t h e experimental e r r o r of d a i l y individual v a r i a t i o n because of physical o r mental conditions. A scorer should have a high degree of i n t e g r i t y, be able t o concent r a t e and develop an objective and s c i e n t i f i c a t t i t u d e towards scoring meat or o t h e r foods, and above a l l be w i l l i n g t o spend t i m e and e f f o r t needed for a falr evaluation of t h e problem. If t h e members of t h e panel are t o be selected on t h e i r s e n s i t i v i t y of organoleptic ratings, t h e concenms a t present seems t o favor using the food t o be scored as a basis of selection instead o f d i l u t e salt solutions, sugar solution, e t c. I n panel t a s t i n g it is t h e a b i l i t y of the scorer t o detect a flavor i n a mixture of flavors t h a t i s important. Probably t h e most common t e s t used a t present f o r t h e selection of a scoring panel i n t h e t r i a n g u l a r one. Prospective scorers are given t h r e e samples of meat. The samples a r e c u t from a p a r t i c u l a r muscle, a l l t h e same s i z e. The scorer i s t o l d t h a t two samples are duplicates and asked t o pick out t h e duplicates. It i s advantageous t o ask upon what c h a r a c t e r i s t i c a, such as aroma, t a s t e, a f t e r taste, texture, tenderness, and/or juiciness t h e decision i s made, Some persons w i l l t r y t o make t h e s e l e c t i o n on t a s t e alone instead of using a l l p a l a t a b i l i t y f a c t o r s. This l a c k of observation on t h e p a r t of t h e prospective scorer can be c a l l e d t o his a t t e n t i o n in t h e preliminary t r a i n i n g. I n the t r i a n g u l a r t e s t a person has t o pick t h e duplicates 5 times out of 7 f o r t h e results t o be s i g n i f i c a n t. Persons who cannot detect differences i n t h e samples and who cannot duplicate t h e i r judgments i n picking duplicate samples should n o t be placed on t h e scoring panel. Members of a panel should be given preliminary t r a i n i n g i n a6 wide v a r i a t i o n i n q u a l i t i e s of meat as possible. This v a r i a t i o n should preferably be greater than w i l l be m e t i n t h e study. Preparation of and Scoring o f t h e Sample The sample should be presented t o t h e scorer i n an a t t r a c t i v e manner. A l l samples are coded, but coding does not mean t h a t t h e sample should be placed over a l a r g e red o r black pencilled number o r presented i n such a manner t h a t t h e scorer i s adversely affected. The s c o r e r ' s f i r s t reaction i s usually t o t h e appearance o f t h e sample. Each scorer is given a sample, a8 nearly as possible, from the same anatomical location of each cut. This i s important f o r d i f f e r e n t p a r t s of t h e c u t may vary i n composition of f i b e r and connective t i s s u e. I n addition, a center s l i c e has not been subjected t o heat during cooking as long as a s l i c e close t o t h e e x t e r i o r of t h e cut, p a r t i c u l a r l y i n meat cooked rare o r medium done.

4 114. The temperature of t h e neat sample should be about t h e same f o r each scoring, o r t h e scorer may be handicapped. Odor i s more intense when t h e meat temperature i s high. I n addition, the a b i l i t y t o d i f f e r e n t i a t e t h e four tastes ( b i t t e r, sour, salt, and m e e t ) (Moncrieff, 1946, Chapter 5) i s doubled on raising t h e temperature from 1 0 ' t o 20%. Acuteness of taste then i s f a i r l y steady from 2OoC t o 3@C, then falls o f f a s t h e temperature i s raised from 30' t o 4 0 ' C. I n h i s summary Moncrieff (p 125) give8 t h e optimum temperature f o r taste d i f f e r e n t i a t i o n a8 200 t o 4OoC. S l i c e s of meat a r e thickness. Preferably, from i t s r e l a t i v e tenderness, t h e gives sections of the f i b e r s length as possible. cut acros8 t h e t h e standpoint meat should be and connective f i b e r and should be of uniform of chewing t h e sample t o determine s l i c e d on 8 s l i c i n g machine. This tissue with a s nearly uniform Samples should be l a r g e enough f o r the scorer t o have more than one taste. Crocker thinks it i s preferable t o w a i t long enough between bites f o r the s a l i v a t o c l e a r the mouth r a t h e r than e a t other food or drink water o r beverage between samples. It should a l s o be indicated t h a t i f another food o r a drink i s used between samples, it should a l s o be used before s t a t i n g t o score the first sample. Moncrieff (1946) s t a t e s t h a t the sweet t a s t e is most e a s i l y perceived a t t h e t i p of the tongue, the b i t t e r a t the back, t h e sour a t t h e edge, and t h e salt a t both the t i p and edge, Crocker (1945) gives a somewhat d i f f e r e n t dist r i b u t i o n of t h e t a s t e buds. I n 80me areas two o r a l l of t h e t a s t e s can be distinguished and there i s an area a l i t t l e l e e s than the size of a dime back of t h e tongue t i p i n which no taste i s perceived. Other areas i n which t a s t e buds a r e located i n addition t o t h e dorsal p a r t o f t h e tongue, a r e t h e s o f t palate, t h e e p i g l o t t i s, and the beginning of the esophagus. It i a not necessary f o r us t o decide whether Moncrieff o r Crocker i s r i g h t. It i s indicated though that i n t h e preliminary t r a i n i n g t h e prospective scorer should not swallow the sample too h a s t i l y, but should develop a d e f i n i t e procedure of r o l l i n g t h e sample over the tongue between chews. I n addition, t o the t a s t e buds being located i n d i f f e r e n t areas, some t a s t e perceptions a r e i d e n t i f i e d more slowly than others. The four t a s t e s i n order of ease of detection a r e b i t t e r, sour, salt, and sweet, It i s the combined result of a l l of these t a s t e and odor perceptions t h a t determine the r e l a t i v e p a l a t a b i l i t y of two o r more samples of meat. A good scorer develops a procedure t o obtain as much information a b u t each sample as possible, The scorer should not be interrupted during scoring. be done i n a place f r e e of odors of other materials and foods. Scoring should Each ecorer, after the preliminary training, works independently. There i s no d e f i n i t e r u l e i n deciding upon t h e number of samples that can be ecored a t one t i m e. The senses of t a s t e and smell fatigue e a s i l y, hence t h e number should not be large. The number of samples that can be scored a t one t i m e i s a l s o r e l a t e d t o t h e number of p a l a t a b i l i t y f a c t o r s t o be scored. If the score card i s complicated two samples &re s u f f i c i e n t f o r scoring. I f only p a r t of t h e p a l a t a b i l i t y f a c t o r s a r e t o be rated, then four o r more samples may be scored a t one t i m e.

5 115, Subjective and Objective Tests Subjective tenderness and j u i c i n e s s of t h e meat r a t i n g s may be compared with objective shear force (pounde o r ounces t o shear a cylinder of a d e f i n i t e s i z e ) and press f l u i d. The amount of press f l u i d can be determined by t h e Carver prees of t h e Minnesota pressometer. We have found t h a t counting t h e number of chews t o masticate a standard s i z e sample t o a predetermined end point gives a very easy way of evaluating comparative tenderness i n d i f ferent samples. Do not be surprised i f objective tests and subjective t e s t s do n o t always agree. They may be measuring d i f f e r e n t things. For example, t h e r e are some meats, which with t h e first b i t e l o s e a great deal of juice. A f t e r a f e w chews, t h e meat may become dry i n t h e mouth, The sample may be r a t e d dry on an organoleptic rating, y e t give a high percentage of press f l u i d. Evaluation of Tests Usually t h e study i s not complete u n t i l t h e scoring data have been analyzed by some standard s t a t i s t i c a l methods t o t e s t t h e significance of t h e data. L i t e r a t u r e Cited Bouthilet, R. J., A note on t h e flavor constituent of poultry meat, Food Tech, 3: 118 Crocker, E.C., Flavor, Crocker, E.C., Flavor of meat, Food Research 13: Moncrieff, R.W., pp. McGraw-Hill Book Company, I n c. The chemical senses, CHAIRMAN BUTLER: 172 pp John Wiley and Sons, Inc., Thank you, Miss Lowe. The discussion w i l l be directed by V. K. Johnson of Illinois. PROF, JOHNSON: A r e t h e r e any questions t h a t you would l i k e t o d i r e c t t o Miss Lowe? PROF. WANDERSTOCK: Miss Lowe, do you t h i n k t h a t it i s advisable, i n s e t t i n g up a p a l a t a b i l i t y panel f o r a meat study, t o have your committee g e t together and have a trial run? MISS LOWE: Oh, yes, t h a t i s a preliminary t r a i n i n g, p a r t i c u l a r l y i f they have not been judging, o r i f you have been judging f o r t h i r t y years, like I have, and you had a vacation during t h e summer, you need t o r e f r e s h before you go i n. PROF. JOHNSON: Anybody else? PROF, KLINE: Miss Lowe, would you use t h e p a l a t a b i l i t y committee a f t e r they have eaten, o r j u s t before they have eaten, o r does t h a t seem t o make much difference?

6 116. MISS LOWE: Most of ours we use a t the time that it i s very easy; usually about eleven o'clock, because t h e meat w i l l come out about that time. I r a t h e r gather, i f I remember Moncrieffrightly, t h a t that i s a p r e t t y good t i m e t o score, I n t h e af'ternoon, we usually score a t about four o'clock. There m e some t h a t advocate e a r l i e r than that. I remember in our first p a l a t a b i l i t y t e s t, a f t e r we s t a r t e d our co-operative meat projects in 1926, that they suggested scoring a t 9:30 a.m. but I think it has not been borne out altogether that t h a t i s t h e b e s t t i m e t o do it. PROF. JOHNSON: Any other questione? If not, I w i l l turn t h e meeting back t o Chairman Butler. CHAIRMAN BVILER: Thank you, M r. Johnson, Prof. Bratzler has been s t a l l i n g me o f f about two days on some quest i o n s I have been asking about tenderness of meat, and we w i l l now have a discussion by him on "Determining t h e Tenderness of Meat by the Use of the WarnerBratzler Method". ###